Weighted average based on sampling of approximately 900 retail outlets, 8:00AM Monday. The price represents self-service unless only full-service is available and includes all taxes. See (http://www.eia.doe.gov/oil_gas/petroleum/data_publications/wrgp/mogas_home_page.html) for further definitions. Premium Gasoline has an antiknock index (average of the research octane rating and the motor octane number) greater than 90. Octane requirements may vary by altitude.